Imaging apparatus

ABSTRACT

An imaging apparatus includes an imaging unit for capturing a subject and generating image data of the subject, an operation input unit for receiving inputs of operation signals containing a release signal for instructing the imaging unit to shoot, an acceleration detector for detecting an acceleration of the imaging apparatus, a state detector for separately detecting a case in which the imaging apparatus is overland, a case in which the imaging apparatus is underwater and a photographer shoots while swimming, and a case in which the imaging apparatus is underwater and the photographer shoots while changing a water depth, and a control unit for performing operation control depending on an input into the operation input unit and/or into the acceleration detector according to a state detection result by the state detector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2009-225363, filed on Sep. 29, 2009,Japanese Patent Application No. 2009-225364, filed on Sep. 29, 2009 andJapanese Patent Application No. 2009-228282, filed on Sep. 30, 2009, theentire contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an imaging apparatus for capturing asubject and generating image data of the subject.

2. Description of the Related Art

In recent years, there has been developed in an imaging apparatus suchas digital camera or digital video camera, a technique having functionssuitable for underwater shooting mounted thereon. For example, there isknown a technique in which a zoom operation and a shooting operation areperformed through a single operation during underwater shooting so asnot to miss a photo opportunity (see Japanese Laid-open PatentPublication No. 2008-83170 Publication, for example). With thistechnique, releasing and zooming can be discriminated depending on thelength of time for which a photo trigger is being pressed and the zoomoperation and the shooting operation can be performed only by the phototrigger.

SUMMARY

An imaging apparatus according to the present invention includes: animaging unit for capturing a subject and generating image data of thesubject; an operation input unit for receiving inputs of operationsignals containing a release signal for instructing the imaging unit toshoot; an acceleration detector for detecting an acceleration of theimaging apparatus; a state detector for separately detecting a case inwhich the imaging apparatus is overland, a case in which the imagingapparatus is underwater and a photographer shoots while swimming, and acase in which the imaging apparatus is underwater and the photographershoots while changing a water depth; and a control unit for performingoperation control depending on an input into the operation input unitand/or into the acceleration detector according to a state detectionresult by the state detector.

The above and other features, advantages and technical and industrialsignificance of this invention will be better understood by reading thefollowing detailed description of presently preferred embodiments of theinvention, when considered in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a configuration of an imagingapparatus according to a first embodiment of the present invention;

FIG. 2 is a diagram showing a situation in which the imaging apparatusaccording to the first embodiment of the present invention performscharacteristic processes;

FIG. 3 is a diagram showing a temporal water depth change when aphotographer shoots while skin diving;

FIG. 4 is a flowchart showing an outline of processes to be performed bythe imaging apparatus according to the first embodiment of the presentinvention;

FIG. 5 is a block diagram showing a configuration of an imagingapparatus according to a second embodiment of the present invention;

FIG. 6 is a diagram showing a configuration of an acceleration sensorwhich is part of an acceleration detector provided in the imagingapparatus according to the second embodiment of the present invention;

FIG. 7 is a diagram schematically showing a configuration of theacceleration detector provided in the imaging apparatus according to thesecond embodiment of the present invention;

FIG. 8 is a diagram showing a situation in which the photographer taps asurface of the imaging apparatus according to the second embodiment ofthe present invention;

FIG. 9 is a diagram schematically showing detectable areas of a holddetector in the imaging apparatus according to the second embodiment ofthe present invention;

FIG. 10 is a diagram showing a situation in which the photographer holdsthe imaging apparatus according to the second embodiment of the presentinvention with the hand;

FIG. 11 is a diagram showing a holding form and a switch operation'sdifficulty level depending on a usage situation of the imaging apparatusaccording to the second embodiment of the present invention;

FIG. 12 is a flowchart showing an outline of processes to be performedby the imaging apparatus according to the second embodiment of thepresent invention;

FIG. 13 is a diagram showing a display example of a display unit whenthe photographer taps a side surface of the imaging apparatus accordingto the second embodiment of the present invention;

FIG. 14 is a diagram showing a situation in which the photographer tapsthe top surface of the imaging apparatus according to the secondembodiment of the present invention;

FIG. 15 is a diagram showing a display example of the display unit inthe imaging apparatus according to the second embodiment of the presentinvention when auxiliary light projection is set by an auxiliary lightprojector during shooting;

FIG. 16 is a block diagram showing a configuration of an imagingapparatus according to a third embodiment of the present invention;

FIG. 17 is a diagram schematically showing a configuration of anacceleration detector in the imaging apparatus according to the thirdembodiment of the present invention;

FIG. 18 is a diagram showing a situation in which the photographer usesthe imaging apparatus according to the third embodiment of the presentinvention to shoot while swimming immediately below the water surface;

FIG. 19 is a diagram showing a temporal water depth change of theimaging apparatus when the photographer uses the imaging apparatusaccording to the third embodiment of the present invention to shootunderwater;

FIG. 20 is a flowchart showing an outline of processes to be performedby the imaging apparatus according to the third embodiment of thepresent invention;

FIG. 21 is a diagram showing an outline of a motion-sensing activationprocess to be performed by the imaging apparatus according to the thirdembodiment of the present invention;

FIG. 22 is a diagram showing a situation in which the photographer putsthe imaging apparatus according to the third embodiment of the presentinvention into his/her shirt breast pocket;

FIG. 23 is a diagram showing a situation in which the photographer takesthe imaging apparatus according to the third embodiment of the presentinvention out of his/her shirt breast pocket and is ready to shoot;

FIG. 24 is a diagram showing a temporal change in gravity accelerationper component in a coordinate system specific to the imaging apparatuswhen the imaging apparatus changes from the situation in FIG. 22 to thesituation in FIG. 23;

FIG. 25 is a flowchart showing an outline of processes to be performedby an imaging apparatus according to a fourth embodiment of the presentinvention;

FIG. 26 is a block diagram showing a configuration of an imagingapparatus according to a fifth embodiment of the present invention;

FIG. 27 is a diagram showing an operation's difficulty level and anecessity for play mode in underwater shooting and overland shooting;

FIG. 28 is a diagram showing setting contents depending on the number oftimes of tapping when the imaging apparatus according to the fifthembodiment of the present invention is set in the underwater shootingmode;

FIG. 29 is a flowchart showing an outline of processes when the imagingapparatus according to the fifth embodiment of the present invention isset in the underwater shooting mode;

FIG. 30 is a diagram showing a display example of an operation mode in adisplay unit provided in the imaging apparatus according to the fifthembodiment of the present invention;

FIG. 31 is a diagram showing a display example (second example) of theoperation modes in the display unit provided in the imaging apparatusaccording to the fifth embodiment of the present invention;

FIG. 32 is a diagram showing an outer configuration of the rear surfaceof the imaging apparatus according to the fifth embodiment of thepresent invention;

FIG. 33 is a diagram showing setting contents (second example) dependingon the number of times of tapping when the imaging apparatus accordingto the fifth embodiment of the present invention is set in theunderwater shooting mode;

FIG. 34 is a flowchart showing an outline of processes when an imagingapparatus according to a sixth embodiment of the present invention isset in the underwater shooting mode;

FIG. 35 is a block diagram showing a configuration of an imagingapparatus according to a seventh embodiment of the present invention;

FIG. 36 is a flowchart showing an outline of processes when the imagingapparatus according to the seventh embodiment of the present inventionis set in the underwater shooting mode;

FIG. 37 is a diagram showing a situation in which the photographer usesthe imaging apparatus according to the seventh embodiment of the presentinvention to shoot while swimming immediately below the water surface;

FIG. 38 is a diagram showing a situation in which the photographer holdsthe imaging apparatus according to the seventh embodiment of the presentinvention with both hands and taps it with the left hand; and

FIG. 39 is a diagram showing a situation in which the photographer usesthe imaging apparatus according to the seventh embodiment of the presentinvention to shoot while skin diving.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments for implementing the present invention (which will bereferred to as “embodiments” below) will be described below withreference to the accompanying drawings.

First Embodiment

FIG. 1 is a block diagram showing a configuration of an imagingapparatus according to a first embodiment of the present invention. Animaging apparatus 1 shown in FIG. 1 includes an imaging unit 2 forcapturing a subject and generating electronic image data of the capturedimage, an image processor 3 for performing image processes such as edgeenhancement, color correction and image compression on the image datagenerated by the imaging unit 2, a display unit 4 for displayinginformation containing an image corresponding to the image dataprocessed by the image processor 3, an operation input unit 5 forreceiving inputs of various operation signals of the imaging apparatus1, a water depth detector 6 for detecting a water depth of the imagingapparatus 1 at a predetermined period, a water depth change calculator 7for calculating the amount of change in water depth detected by thewater depth detector 6, a clock 8 having a shooting time/date decisionfunction and a timer function, an auxiliary light projector 9 forprojecting an auxiliary light onto a viewing area of the imaging unit 2,a storage unit 10 for storing therein various items of informationcontaining the image data processed by the image processor 3, a controlunit 11 for controlling operations of the imaging apparatus 1 accordingto the operation signals input by the operation input unit 5, and apower supply unit 12 for supplying power to the respective parts in theimaging apparatus 1 under control of the control unit 11.

The imaging unit 2 includes an optical system which is configured withone or multiple lenses and is for condensing lights from a subjectpresent in a predetermined viewing area, a diaphragm which adjusts theamount of incident lights condensed by the optical system, a shutterwhich operates in response to a release input, an imaging device such asCharge Coupled Device (CCD) which receives a light passing through thediaphragm and the shutter and converts it into an electric signal, and asignal process circuit which performs signal processes such asamplification and white balancing on an analog signal output from theimaging device and then generates digital image data by A/D conversion.

The display unit 4 is provided on a surface (rear surface) opposite to asurface (front surface) on which the optical system of the imaging unit2 is present, and displays operation information or shooting informationof the imaging apparatus 1 as well as the image data as needed. Thedisplay unit 4 is realized with a display panel made of liquid crystal,plasma or organic Electro Luminescence (EL).

The operation input unit 5 includes a release switch for inputting arelease signal and a power supply switch for inputting power-on andpower-off instruction signals. In the first embodiment, “power-on” meansa transition to a state where the power supply unit 12 can supply powerto the entire imaging apparatus 1, and “power-off” means that the powersupply unit 12 stops supplying power to the entire imaging apparatus 1.

The water depth detector 6 is realized with a water pressure sensor. Awater pressure detected by the water pressure sensor is on the order of1060 hPa at a water depth of 50 cm, and becomes higher as the waterdepth is more. The water depth detector 6 has a function of temporarilystoring at least two latest water depth detection results.

When the release switch of the operation input unit 5 is pressed, thewater depth change calculator 7 calculates changes between the twolatest water depths detected and stored by the water depth detector 6.The water depth change calculator 7 has a function of deciding whetherthe detection result by the water depth detector 6 indicates a valuewhich can be regarded as underwater. The water depth change calculator 7calculates a change in water depth when the release button is pressedwhile power is not being supplied to parts containing the imaging unit2. The water depth change calculator 7 calculates a change in waterdepth also when power is being supplied to the entire imaging apparatus1 containing the imaging unit 2 and operation inputting is performedthrough the operation input unit 5 other than the release switch.

The water depth detector 6 and the water depth change calculator 7function as a state detector for discriminating a case where the imagingunit 2 is underwater and shooting is done in a floating state with lesswater depth change from a case where the imaging unit 2 shootsunderwater with large water depth change.

The storage unit 10 includes an image data storage unit 101 for storingtherein the image data shot by the imaging unit 2 and processed by theimage processor 3, and a program storage unit 102 for storing thereinvarious programs to be executed by the imaging apparatus 1. The storageunit 10 is realized with a semiconductor memory such as flash memory orRandom Access Memory (RAM) fixedly provided inside the imaging apparatus1. The storage unit 10 may function as a recording medium interface forrecording information in an externally-mounted recording medium such asmemory card and reading out information recorded in the recordingmedium.

The control unit 11 includes a shooting controller 111 for controllingthe shooting by the imaging unit 2 and a power supply controller 112 forcontrolling the power supplying by the power supply unit 12. The controlunit 11 is realized with a Central Processing Unit (CPU) and isconnected to the respective parts in the imaging apparatus 1 via a busline.

The power supply unit 12 always supplies power to the operation inputunit 5, the water depth detector 6, the water depth change calculator 7,the clock 8 and the power supply controller 112 irrespective of whetherthe imaging apparatus 1 has been activated by the power supply switch.Thus, the operation input unit 5, the water depth detector 6, the waterdepth change calculator 7, the clock 8 and the power supply controller112 are being always activated. The operation input unit 5, the waterdepth detector 6, the water depth change calculator 7, the clock 8 andthe power supply controller 112 are referred to as always-on parts.

If power supplying is desired to be significantly reduced, the always-onparts may be changed depending on mode setting. For example, if theunderwater shooting mode can be manually set, power may be supplied tothe water depth detector 6 and the water depth change calculator 7 onlywhen the underwater shooting mode is set.

The above-configured imaging apparatus 1 has on its exterior awaterproof casing whose surfaces are tightly sealed. The waterproofcasing is disclosed in Japanese Laid-open Patent Publication No.2008-180898, for example.

FIG. 2 is a diagram showing a situation in which the features of theimaging apparatus 1 are expressed. Specifically, FIG. 2 shows asituation in which a photographer M is underwater and uses the imagingapparatus 1 for underwater shooting. Under the situation, thephotographer M has to hold his/her breath underwater. Thus, thephotographer M is likely to rapidly surface immediately after shooting.A water depth d of the imaging apparatus 1 before and after thephotographer M shoots underwater changes as a curved line L indicated inFIG. 3. In FIG. 3, the horizontal axis indicates time t and the verticalaxis indicates water depth d (positive in the downward direction).

When heavily-equipped diving is performed such as scuba diving, aholding form of the imaging apparatus 1 has a high degree of freedomduring still image shooting or moving picture shooting. The firstembodiment assumes that the shooting by the imaging apparatus 1 iscontrolled when the photographer goes under the water to a water depthof about 5 m which is reachable by skin diving. “Skin diving” in thefirst embodiment includes snorkeling but does not includeheavily-equipped diving such as scuba diving. The same is applied to thesecond to seventh embodiments described later.

While the photographer M is underwater with the imaging apparatus 1, thephotographer M can only press the release switch of the operation inputunit 5. Thus, in the first embodiment, the power supply controller 112supplies power to the entire imaging apparatus 1 (turns on the powersupply) when the release switch is pressed while the water depth changeper predetermined time is larger than a predetermined threshold.Thereafter, the shooting controller 111 changes the shooting conditionssuch as exposure time and gain in the imaging unit 2 and thencontinuously takes a predetermined number of photos. More specifically,since the photographer easily reels underwater, the shooting controller111 reduces the exposure time and enhances the gain, thereby improvingsensitivity. With the controlling, the photographer which cannot freelymove underwater and is difficult to adjust the shooting timing canaccurately shoot a desired subject.

FIG. 4 is a flowchart showing an outline of processes to be performed bythe imaging apparatus 1. In FIG. 4, when the release switch of theoperation input unit 5 is operated (step S1: Yes), the water depthchange calculator 7 calculates the amount of change Δd between twolatest water depths detected by the water depth detector 6 (step S2). Asa result of the calculation by the water depth change calculator 7, whenthe amount of change Δd in water depth is larger than a first thresholdH (>0) (step S3: Yes), the power supply controller 112 controls thepower supply unit 12 to supply power to each unit in the imagingapparatus 1 (step S4). The transition to a state where the power supplyunit 12 can supply power to the entire imaging apparatus 1 will bereferred to as “power-on” below. The first threshold H may employ avalue of about 1 m. A detection period Δt of the water depth detector 6may be on the order of 2 seconds.

After the shooting controller 111 has changed the shooting conditions(step S5), the powered-on imaging apparatus 1 causes the imaging unit toshoot (step S6). Specifically, the shooting controller 111 sets theexposure time of the imaging unit 2 to be shorter than the initialsetting and enhances the gain of the imaging unit 2 to be higher thanthe initial setting, and then causes the imaging unit 2 to take apredetermined number (such as five) of photos serially. If the shootingcontroller 111 causes the auxiliary light projector 9 to project anauxiliary light, a red-color component, which is easily lost underwater,can be compensated and a vivid image can be shot, which is preferable.

Thereafter, when the operation input unit 5 is operated within apredetermined time (such as 1 minute) (step S7: Yes) and when theoperation is by the release switch (step S8: Yes), the imaging apparatus1 returns to step S6. On the other hand, when the operation by theoperation input unit 5 is not the release switch operation (step S8:No), the water depth change calculator 7 uses the two latest detectionresults by the water depth detector 6 to calculate the amount of changeΔd in water depth (step S9).

When the calculation result in step S9 is smaller than a secondthreshold −H (step S10: Yes), the power supply controller 112 controlsthe power supply unit 12 to stop supplying power to the entire imagingapparatus 1 other than the always-on parts (step S11). The process instep S11 will be referred to as “power-off” below. As far as the secondthreshold has a different sign from the first threshold H, they do nothave to have the same absolute value. The imaging apparatus 1 performsstep S11 and then returns to step S1.

When the operation input unit 5 is not operated within the predeterminedtime in step S7 (step S7: No), the imaging apparatus 1 proceeds to stepS11.

When the amount of change Δd in water depth is equal to or more than thesecond threshold −H in step S10 (step S10: No), the imaging apparatus 1returns to step S7. When the imaging apparatus returns from step S10 tostep S7, the clock 8 performs measurements while setting the time pointof the latest operation (other than the release operation) to zero.

There will be described a case in which the release signal is not inputin step S1 (step S1: No) and the amount of change Δd is equal to or lessthan H in step S3 (step S3: No). In the case, when the power supplyswitch is operated (step S12: Yes), and the power supply switchoperation is the power-on operation (step S13: Yes), the power supplycontroller 112 controls the power supply unit 12 to turn on (step S14).Thereafter, the control unit 11 performs normal control (step S15).“Normal control” means that the controlling is first started in theshooting mode and shooting or mode switching is performed depending onthe inputs of various operation signals from the operation input unit 5.

When the control unit 11 performs normal control and then the power-offoperation is performed (step S16: Yes), the imaging apparatus 1 proceedsto step S11. On the other hand, when the control unit 11 performs normalcontrol and then the power-off operation is not performed (step S16:No), the imaging apparatus 1 continues the normal control (step S15).

When the power supply switch is not operated in step S12 (step S12: No),the imaging apparatus 1 returns to step S1.

When the power supply switch operation is not the power-on operation instep S13 (step S13: No), that is, the power supply switch operation isthe power-off operation, the imaging apparatus 1 proceeds to step S11.

As described above, in the first embodiment, when the amount of changeΔd in water depth exceeds the first threshold H while the power supplyis not being turned on underwater, the power supply is automaticallyturned on, the shooting conditions are changed and then the continuousshooting is started. Thus, if the photographer wants to shoot fisheswhile skin diving, a time from diving to shooting can be reduced and theimages containing fishes are likely to be shot.

According to the first embodiment of the present invention describedabove, since the imaging apparatus is configured to continuously shootpredetermined number of times when the release switch is pressed whilethe water depth becomes rapidly larger due to diving, a desired image islikely to be contained in the continuously-shot images even when thephotographer is concentrating hard on swimming. Thus, the photographercan easily shoot while diving, and is likely to obtain a desired image.

Further, according to the first embodiment, since the power supply isturned off whenever the photographer emerges underwater or the releasesignal is not input, the battery can last long.

Second Embodiment

FIG. 5 is a block diagram showing a configuration of an imagingapparatus according to a second embodiment of the present invention. Animaging apparatus 21 shown in FIG. 5 further includes an accelerationdetector 22 for detecting an acceleration of the imaging apparatus 1 anda hold detector 23 for detecting an external hold at a predeterminedposition of the imaging apparatus 1 in addition to the configuration ofthe imaging apparatus 1.

FIG. 6 is a diagram showing a configuration of an acceleration sensorwhich is part of the acceleration detector 22. An acceleration sensor221 shown in FIG. 6 is a capacitance-type acceleration sensor formed byMicro Electro Mechanical Systems (MEMS) process. The acceleration sensor221 includes a metallic movable part 223 having a beam structure inwhich the ends of the beam are fixedly bridged near the four corners ofthe main surface of a parallelepiped chip 222, and two metallic plateparts 224 provided on the main surface, on which the ends of the movablepart 223 are fixed, of the chip 222. The movable part 223 includes twoextension parts 223 a which extend in a belt shape in the same directionalong the main surface of the chip 222 and both ends of which are fixed,a belt-shaped connection part 223 b which connects the center portionsof the two extension parts 223 a in the orthogonal direction to thedirection in which the extension parts 223 a extend, and a projectionpart 223 c which projects in a belt shape from the center portion of theconnection part 223 b in parallel to the direction in which theextension parts 223 a extend.

When an acceleration in the horizontal direction (in the direction ofarrow) in FIG. 6 is applied to the acceleration sensor 221 having theabove structure, the movable part 223 is flexibly deformed in thehorizontal direction so that the positional relationship between theprojection part 223 c and the plate parts 224 changes and thus thecapacitance changes. The acceleration sensor 221 outputs a signal changebased on the change in capacitance. The acceleration detector 22 can beused for decision on hand's giggling or correction based on thedecision.

FIG. 7 is a diagram schematically showing a configuration of theacceleration detector 22 in the imaging apparatus 21. As shown in FIG.7, the acceleration detector 22 includes three acceleration sensors 221the acceleration detecting directions of which are orthogonal to eachother. With the acceleration detector 22 having the above configuration,when the photographer instantaneously taps a surface of the imagingapparatus 21, the acceleration generated by the tap operation can beaccurately detected.

FIG. 8 is a diagram showing a situation in which the photographer taps asurface of the imaging apparatus 21. When the photographer taps the leftside surface of the surfaces of the imaging apparatus 21 viewed from thefront surface with the forefinger RHf of the right hand RH, theacceleration detector 22 detects an acceleration which has maincomponents in the horizontal direction of FIG. 8 (corresponding to thewidth direction of FIG. 7) and a magnitude larger than a predeterminedvalue which can be regarded as tap, and which indicates a pulse-shapedtemporal change. Thus, it is possible to decide that the imagingapparatus 21 has been tapped. The predetermined value is set such that atap signal is not generated unless the photographer consciously taps theimaging apparatus 21. Specifically, the predetermined value may be setas large as the gravity acceleration (9.8 m/s²), for example. The pulsewidth of vibration applied by tapping is on the order of 5 msec whilethe pulse width of vibration applied by user's walking is on the orderof 30 msec. When the acceleration magnitude and the pulse width are usedtogether, it is possible to decide whether a signal applied to theimaging apparatus is the tap signal. When the imaging apparatus 21 isunderwater, the predetermined value may be set to be smaller inconsideration of water resistance.

The imaging apparatus 21 has a function of preventing unintentionalpower-on by tapping overland. This is because a tapping-like vibrationis likely to occur when the photographer walks with the imagingapparatus 21 overland.

In FIG. 8, two buttons 5 a and 5 b provided on the top surface of theimaging apparatus 21 are the release switch and the power supply switch,respectively. In the following, the button 5 a is referred to as releaseswitch 5 a and the button 5 b is referred to as power supply switch 5 b.

FIG. 9 is a diagram schematically showing detectable areas of the holddetector 23. The hold detector 23 has a function of detecting thepresence of external contact on rectangular areas 211L and 211R providedat the right and left ends on the front surface of the imaging apparatus21. The hold detector 23 having the function is realized by arrangingone or multiple pressure sensors inside each rectangular area, forexample. When the photographer holds the imaging apparatus 21 with bothhands, the hold detector 23 detects external contact on the rectangularareas 211L and 211R. On the other hand, when the photographer holds theimaging apparatus 21 with either hand, the hold detector 23 detectsexternal contact on either one of the rectangular areas 211L and 211R.

For the imaging apparatus 21 shown in FIG. 9, since the release switch 5a and the power supply switch 5 b are provided on the top surface to theright viewed from the photographer, the photographer is likely to holdthe imaging apparatus 21 with the right hand RH as shown in FIG. 10.Thus, when the photographer holds the imaging apparatus 21 with eitherhand, the hold detector 23 is likely to detect external contact on therectangular area 211R.

The acceleration detector 22 and the hold detector 23 are always beingsupplied with power from the power supply unit 12 and are beingactivated similarly to the operation input unit 5, the water depthdetector 6, the water depth change calculator 7 and the clock 8.

FIG. 11 is a diagram showing a holding form and a switch operation'sdifficulty level for still image shooting and moving picture shootingdepending on a usage situation of the imaging apparatus 21. When thephotographer shoots while skin diving (see FIG. 2), the photographer islikely to use either hand for swimming. Under the situation, when thephotographer holds the imaging apparatus 21 with either hand, theimaging apparatus 21 is preferably controlled for still image shooting.In the second embodiment, when the photographer shoots while skindiving, the shooting controller 111 changes the shooting conditions suchas exposure and gain for serially taking photos like in the firstembodiment. The imaging apparatus 21 is set such that moving pictureshooting cannot be done when the photographer holds the imagingapparatus 21 with either hand.

To the contrary, since the photographer is in a relatively stableposture while he/she is swimming immediately below the water surface,the photographer can easily perform the switch operation and hold theimaging apparatus 21 with both hands. For moving picture shooting, thephotographer can shoot while moving the imaging apparatus 21 with eitherhand. Under the situation, the imaging apparatus 21 is set such thatstill image shooting is performed when the photographer holds theimaging apparatus 21 with both hands while moving picture shooting isperformed when the photographer holds the imaging apparatus 21 witheither hand.

When the photographer uses the imaging apparatus 21 overland, thecontrol unit 11 performs normal control. In other words, when theimaging apparatus 21 is overland, the control unit 11 switches stillimage shooting and moving picture shooting through the switch operation.

As described above, in the second embodiment, it is possible to performoptimal control depending on a usage situation of the imaging apparatus21.

FIG. 12 is a flowchart showing an outline of processes to be performedby the imaging apparatus 21. There will be first described a case inwhich the acceleration detector 22 detects a tap or the hold detector 23detects a hold (step S21: Yes). In this case, the water depth changecalculator 7 refers to the result detected by the water depth detector6, and when the latest detection result indicates a value which can beregarded as underwater (step S22: Yes), calculates the amount of changeΔd between the two latest water depths detected by the water depthdetector 6 (step S23). In order to detect whether the imaging apparatus21 is underwater, a water detection switch, which is in a state ofconduction by water between two electrodes, may be provided on thesurface of the imaging apparatus 21.

As a result of the calculation of the amount of change Δd in water depthby the water depth change calculator 7, when the absolute value |Δd| issmaller than a third threshold h (0<h<H) and the water depth can beregarded as constant (step S24: Yes), that is, when the photographer isswimming immediately below the water surface, and the imaging apparatus21 is in the power-on state (step S25: Yes), the power supply controller112 turns off the power supply (step S26) and returns to step S21. Thethird threshold h is about 30 to 35 cm, for example.

When the imaging apparatus 21 is not in the power-on state in step S25(step S25: No), the power supply controller 112 turns on the powersupply and then the display unit 4 displays the image captured by theimaging unit 2 as through-image (step S27).

When a predetermined time (such as three minutes) has elapsed after thestart of the through-image display by the display unit 4 (step S28:Yes), the imaging apparatus 21 proceeds to step S26.

When a predetermined time has not elapsed after the start of thethrough-image display by the display unit 4 (step S28: No) and when therelease switch 5 a is operated (step S29: Yes), the subsequent processesare differently performed depending on the detection result by the holddetector 23. First, as a result of the detection by the hold detector23, when the imaging apparatus 21 is held by both hands (step S30: Yes),the imaging apparatus 21 performs still image shooting (step S31) andreturns to step S29. To the contrary, as a result of the detection bythe hold detector 23, when the imaging apparatus 21 is held by eitherhand (step S30: No), the imaging apparatus 21 performs moving pictureshooting (step S32) and returns to step S29.

When the release switch 5 a is not operated in step S29 (step S29: No),the imaging apparatus 21 returns to step S28.

Next, there will be described a case in which the water depth is notconstant in step S24, that is, a case of |Δd|≧:h (step S24: No). In thiscase, when the amount of change Δd in water depth is larger than thefirst threshold H (step S33: Yes), that is, when the photographer isunderwater, and the release switch 5 a of the operation input unit 5 isoperated (step S34: Yes), the power supply controller 112 turns on thepower supply and then the display unit 4 displays a through-image (stepS35). The processes in step S36 to S42 subsequent to step S35sequentially correspond to the processes in step S5 to S11 in FIG. 4.The power supply controller 112 turns off the power supply in step S42and then the imaging apparatus 21 returns to step S21.

When the amount of change Δd in water depth is equal to or less than thefirst threshold H in step S33 (step S33: No) and the release switch 5 ais not operated in step S34 (step S34: No), the imaging apparatus 21returns to step S22.

There will be described the processes to be continuously performed whenthe acceleration detector 22 detects no tap and the hold detector 23detects no hold in step S21 (step S21: No) and when the value of thelatest detection result by the water depth detector 6 cannot be regardedas underwater in step S22 (step S22: No). The processes in step S43 toS47 to be subsequently performed correspond to the processes in step S12to S16 in FIG. 4 sequentially.

When the power supply switch is not operated in step S43 (step S43: No),the imaging apparatus 21 returns to step S21.

When the power supply switch is not turned on in step S44 (step S44: No)and the power supply is turned off in step S47 (step S47: Yes), theimaging apparatus 21 proceeds to step S42.

When the power supply is not turned off in step S47 (step S47: No), theimaging apparatus 21 continues normal control (step S46).

According to the second embodiment of the present invention describedabove, since the imaging apparatus is configured such that if therelease switch is pressed when the water depth is rapidly changing dueto diving, shooting is continuously done predetermined number of times,a desired image is likely to be found in the continuously-shot imageseven if the photographer is concentrating hard on swimming. Thus, thephotographer can easily shoot while diving and is likely to obtaindesired images.

According to the second embodiment, since the power supply is turned offwhenever the photographer emerges underwater or the release signal isnot input, the battery can last long.

According to the second embodiment, still image shooting and movingpicture shooting are switched depending on the holding form of theimaging apparatus by the photographer during diving and thus optimalcontrol can be performed depending on the diving situation of thephotographer.

In the second embodiment, when the imaging apparatus 21 is overland,various switch operations such as activation of the imaging apparatus 21may be input by the tap operation. Specific examples thereof will bedescribed below.

For example, as shown in FIG. 8, when the photographer taps a sidesurface of the imaging apparatus 21, the power supply of the imagingapparatus 21 may be automatically turned on. FIG. 13 is a diagramshowing a display example of the display unit 4 when the photographertaps a side surface of the imaging apparatus 21 under the setting. InFIG. 13, the display unit 4 displays thereon a message of “self ON”indicating that the power supply has been automatically turned on, and aleftward arrow in addition to a through image.

As shown in FIG. 14, the imaging apparatus 21 may be set such that whenthe top surface of the imaging apparatus 21 is tapped by the forefingerRHf, the auxiliary light projector 9 projects an auxiliary light duringshooting. FIG. 15 is a diagram showing a display example of the displayunit 4 when the projection of an auxiliary light by the auxiliary lightprojector 9 is set during shooting. In FIG. 15, the display unit 4display thereon a message of “STON” indicating that the auxiliary lightprojector 9 projects an auxiliary light during shooting, and a downwardarrow in addition to a through-image.

Third Embodiment

FIG. 16 is a block diagram showing a configuration of an imagingapparatus according to a third embodiment of the present invention. Animaging apparatus 301 shown in FIG. 16 includes the imaging unit 2, theimage processor 3, the display unit 4, the operation input unit 5, thewater depth detector 6, the water depth change calculator 7, the clock8, the auxiliary light projector 9, the storage unit 10, the controlunit 11, the acceleration detector 22 and the hold detector 23. Theimaging apparatus 301 includes a posture decision unit 302 for decidinga posture of the imaging apparatus 301 based on a detection result of agravity acceleration by the acceleration detector 22. The same parts asthose of the imaging apparatus 1 are denoted with the same numerals.

In the third embodiment, the water depth detector 6 functions as asecond state detector for discriminating the underwater imaging unit 2from the overland imaging unit 2.

The acceleration detector 22 includes the three acceleration sensors 221the acceleration detecting directions of which are orthogonal to eachother. In the third embodiment, as shown in FIG. 17, the coordinatesystem specific to the imaging apparatus 301 (which will be referred toas “imaging coordinate system” below) employs the x-axis parallel to thethickness direction of the imaging apparatus 301, the y-axis parallel tothe width direction of the imaging apparatus 301 and the z-axis parallelto the height direction of the imaging apparatus 301, and the threeacceleration sensors 221 for detecting the acceleration components inthe respective axial directions are attached to predetermined positionsof the main body of the imaging apparatus 301.

The posture decision unit 302 is configured in a combination ofcomparator and logic circuit, for example. The posture decision unit 302is provided so that the power-on operation can be realized based on achange in posture of the imaging apparatus 301 overland, as describedlater. The posture decision unit 302 may be realized as part of thecontrol unit 11.

The power supply unit 12 always supplies power to the operation inputunit 5, the water depth detector 6, the water depth change calculator 7,the clock 8, the acceleration detector 22, the hold detector 23, thepower supply controller 112 and the posture decision unit 302irrespective of whether the imaging apparatus 301 has been activated bythe power supply switch. In other words, in the third embodiment, theoperation input unit 5, the water depth detector 6, the water depthchange calculator 7, the clock 8, the acceleration detector 22, the holddetector 23, the power supply controller 112 and the posture decisionunit 302 correspond to the always-on parts.

The above-configured imaging apparatus 301 has on its exterior awaterproof casing whose surfaces are tightly sealed like the imagingapparatus 1.

As shown in FIG. 2, the imaging apparatus 301 is characterized by theprocesses when the photographer M shoots underwater while skin diving.Further, as shown in FIG. 18, the imaging apparatus 301 is characterizedby the processes when the photographer M shoots while swimmingimmediately below the water surface, which are different from theunderwater shooting.

FIG. 19 is a diagram showing a temporal change in water depth of theimaging apparatus 301. In FIG. 19, the horizontal axis t indicates timeand the vertical axis d indicates water depth. A curved line L1indicated in FIG. 19 is the same as the curved line L shown in FIG. 3,and indicates a temporal change in water depth of the imaging apparatus301 under the situation shown in FIG. 2. A curved line L2 in FIG. 19indicates a temporal change in water depth of the imaging apparatus 301when the photographer M is swimming immediately below the water surfaceas shown in FIG. 18. As indicated by the curved line L2, when thephotographer M is swimming immediately below the water surface, thewater depth d of the imaging apparatus 301 is substantially constantirrespective of elapsed time.

Like the imaging apparatus 1, the imaging apparatus 301 reduces theexposure time and enhances the gain thereby to improve the sensitivitysince the photographer easily reels underwater. With the controlling,the photographer, who cannot freely move underwater and can barelyadjust the shooting timing, can accurately shoot a desired subject.

FIG. 20 is a flowchart showing an outline of processes to be performedby the imaging apparatus 301. In FIG. 20, when the release switch 5 a ofthe operation input unit 5 is operated (step S101: Yes), the water depthchange calculator 7 calculates the amount of change Δd between the twolatest water depths detected by the water depth detector 6 (step S102).As a result of the calculation by the water depth change calculator 7,when the amount of change Δd in water depth is larger than a fifththreshold H₅ (>0) (step S103: Yes), and the imaging apparatus 301 is notpowered on (step S104: No), the power supply controller 112 controls thepower supply unit 12 to turn on (step S105). The fifth threshold H₅ maybe a value of about 1 m. A detection period Δt of the water depthdetector 6 may be about 2 seconds.

When the imaging apparatus 301 is powered on in step S104 (step S104:Yes), the imaging apparatus 301 proceeds to step S106 described later.

The shooting controller 111 changes the shooting conditions (step S106)and then the powered-on imaging apparatus 301 causes the imaging unit 2to shoot (step S107). Specifically, the shooting controller 111 sets theexposure time of the imaging unit 2 to be shorter than the initialsetting and enhances the gain of the imaging unit 2 as compared with theinitial setting, and then controls the imaging unit 2 to continuouslytake a predetermined number (such as five) of photos serially. At thistime, if the shooting controller 111 causes the auxiliary lightprojector 9 to project an auxiliary light, a red-color component, whichis easily lost underwater, can be compensated and a vivid image can beshot, which is preferable.

Thereafter, when the operation input unit 5 is operated within apredetermined time (such as one minute) (step S108: Yes) and theoperation is by the release switch 5 a (step S109: Yes), the imagingapparatus 301 returns to step S107. On the other hand, when theoperation by the operation input unit 5 is not by the release switch 5 a(step S109: No), the water depth change calculator 7 uses the two latestdetection results by the water depth detector 6 to calculate the amountof change Δd in water depth (step S110), and when the calculation resultis smaller than a predetermined value −H₅ (sixth threshold) (step S111:Yes), the power supply controller 112 controls the power supply unit 12to turn off (step S112). As far as the sixth threshold has a differentsign from the fifth threshold H₅, they do not have to have the sameabsolute value. The imaging apparatus 301 performs step S112 and thenreturns to step S101.

When the operation input unit 5 is not operated within a predeterminedtime in step S108 (step S108: No), the imaging apparatus 301 proceeds tostep S112.

When the amount of change Δd in water depth is equal to or more than thesixth threshold −H₅ in step S111 (step S111: No), the imaging apparatus301 returns to step S108.

There will be described below a case in which the release switch 5 a isnot pressed in step S101 (step S101: No) and the amount of change Δd inwater depth is equal to or less than the fifth threshold H₅ in step S103(step S103: No). In the case, when the acceleration detector 22 detectsa tap or the hold detector 23 detects a hold (step S113: Yes), and thelatest value detected by the water depth detector 6 can be regarded asunderwater (step S114: Yes), the water depth change calculator 7calculates the amount of change Δd between the two latest water depthsdetected by the water depth detector 6 (step S115).

As a result of the calculation of the amount of change Δd in water depthby the water depth change calculator 7, when the absolute value |Δd| issmaller than the fourth threshold h₄ (0<h₄<H₅) at which the water depthcan be regarded substantially constant (step S116: Yes), the powersupply controller 112 controls the power supply unit 12 to turn on (stepS117). On the other hand, when the absolute value |Δd| is equal to ormore than the fourth threshold h₄ (step S116: No), the imaging apparatus301 returns to step S101. The fourth threshold h₄ is about 30 to 50 cm,for example.

After step S117, the control unit 11 performs normal control (stepS118).

Subsequently, when the power supply is turned off (step S119: Yes), theimaging apparatus 301 proceeds to step S112. On the other hand, when thepower supply is not turned off (step S119: No), the imaging apparatus301 continues normal control (step S118).

There will be described below a case in which the value of the latestdetection result by the water depth detector 6 is not regarded asunderwater (step S114: No). In this case, the imaging apparatus 301performs a motion-sensing activation process for turning on the powersupply when a predetermined posture change is detected (step S120). Themotion-sensing activation process will be described below in detail.

After the motion-sensing activation process in step S120, when theimaging apparatus 301 is in the power-on state (step S121: Yes), theimaging apparatus 301 proceeds to step S118. On the other hand, afterthe motion-sensing activation process in step S120, when the imagingapparatus 301 is not in the power-on state (step S121: No), the imagingapparatus 301 returns to step S101.

The motion-sensing activation process will be described below in detail.FIG. 21 is a flowchart showing an outline of the motion-sensingactivation process in step S120. In FIG. 21, the acceleration detector22 detects a gravity acceleration (g_(x), g_(y), g_(z)) in the imagingcoordinate system at a period ΔT₁ (step S201). The period ΔT₁ may beabout 1 second, for example.

As a result of the detection of the gravity acceleration in the imagingcoordinate system by the acceleration detector 22, when a relationshipbetween the gravity acceleration g_(z) in the z-axis direction and thepredetermined value g_(o) changes from “g_(z)≦g₀” to “g_(z)>g_(o)” (stepS202: Yes), the control unit 11 changes the period at which theacceleration detector 22 detects the gravity acceleration to ΔT₂ shorterthan ΔT₁, and causes the acceleration detector 22 to detect the gravityacceleration at the changed period ΔT₂ (step S203). The period ΔT₂ maybe about 1/50 seconds, for example. The predetermined value g₀corresponds to a gravity value when an angle formed between one axis inthe imaging coordinate system and the vertical direction is smaller thana predetermined angel (such as about 45 to 60 degrees), and is a valueat which the gravity acceleration in the axial direction cannot beignored.

On the other hand, as a result of the detection of the gravityacceleration in the imaging coordinate system by the accelerationdetector 22, when the relationship between the gravity accelerationg_(z) in the z-axis direction and the predetermined value g₀ remains“g_(z)≦g₀” (step S202: No), the imaging apparatus 301 returns to stepS201.

After the detection period of the acceleration detector 22 is changedfrom ΔT₁ to ΔT₂ in step S203, the posture decision unit 302 decideswhether the gravity acceleration (g_(x), g_(y), g_(z)) meets apredetermined condition (step S204). The predetermined condition isconcerned with a temporal change in gravity acceleration (g_(x), g_(y),g_(z)). For example, the predetermined condition may be “after eachcomponent of the gravity acceleration is detected predetermined numberof times, the detected value is within a predetermined range”. When avibration pattern is found in the temporal change in each component ofthe gravity acceleration, the period of the vibration may be assumed asthe predetermined condition.

When the gravity acceleration (g_(x), g_(y), g_(z)) meets thepredetermined condition (step S204: Yes), the power supply controller112 controls the power supply unit 12 to turn on (step S205).Thereafter, the imaging apparatus 301 returns to the main routine andproceeds to step S121.

To the contrary, when the gravity acceleration (g_(x), g_(y), g_(z))does not meet the predetermined condition in step S204 (step S204: No),the imaging apparatus 301 returns to the main routine and proceeds tostep S121.

FIGS. 22 and 23 are diagrams showing a situation in which the imagingapparatus 301 is activated by the motion-sensing activation process.Specifically, FIG. 22 shows a situation in which a photographer W iswalking with the imaging apparatus 301 put in a shirt pocket P and FIG.23 shows a situation in which the photographer W takes the imagingapparatus 301 out of the shirt pocket P and is ready to shoot.

When the photographer W is walking with the imaging apparatus 301 in theshirt pocket P, the width direction (corresponding to the y-axisdirection of FIG. 17) is substantially parallel to the verticaldirection, only the y component g_(y) of the gravity acceleration in theimaging coordinate system shown in FIG. 17 has a value larger than thepredetermined value g₀. To the contrary, when the photographer W holdsthe imaging apparatus 301 as shown in FIG. 23, the height direction(corresponding to the z-axis direction of FIG. 17) is substantiallyparallel to the vertical direction, only the z component g_(z) of thegravity acceleration in the imaging coordinate system has a value largerthan the predetermined value g₀.

FIG. 24 is a diagram showing a temporal change in gravity acceleration(g_(x), g_(y), g_(z)) when the imaging apparatus changes from the stateshown in FIG. 22 to the state shown in FIG. 23. In FIG. 24, thehorizontal axis t indicates time and the vertical axis g indicates amagnitude of the gravity acceleration. A curved line L_(x) (indicated bydashed line), L_(y) (indicated by solid line) and L_(z) (indicated bybold line) shown in FIG. 24 indicate the temporal changes in the xcomponent g_(x), the y component g_(y), and the z component g_(z) of thegravity acceleration applied to the imaging apparatus 301, respectively.When the imaging apparatus 301 is in the shirt pocket P of thephotographer W, only the gravity acceleration g_(y) in the y-axisdirection in the imaging coordinate system is larger than thepredetermined value g₀, and other components have the values smallerthan the predetermined value g₀, respectively. To the contrary, when thephotographer W holds the imaging apparatus 301 while being ready toshoot, only the gravity acceleration g_(z) in the z-axis direction islarger than the predetermined value g₀, and other components are smallerthan the predetermined value g₀. FIG. 24 shows a case in which theimaging apparatus 301 is taken out of the shirt pocket P between time t₃and time t₄.

According to the third embodiment of the present invention describedabove, when the tap operation or hold operation is detected underwater,and the water depth does not change so much, power supplying is startedto the entire imaging apparatus and thus the power supply can be easilyturned on under an appropriate condition during underwater shooting.

According to the third embodiment, when the water depth is substantiallyconstant and the tap operation or hold operation is detected, it isrecognized that the photographer positively instructs the imagingapparatus 301 to start the operation, and the power supply is turned on,and thus the operation can be more rapidly performed than pressing asmall switch.

According to the third embodiment, since the imaging apparatus 301 isconfigured such that when the release switch is pressed while the waterdepth becomes rapidly larger due to diving, shooting is continuouslyperformed predetermined number of times, a desired image is likely to befound in the continuously-shot images even if the photographer isconcentrating hard on swimming. Thus, the photographer can easily shootwhile diving and is likely to obtain desired images.

According to the third embodiment, since the power supply is turned offwhenever the photographer emerges underwater or the release signal isnot input, the battery can last long.

When the photographer uses the imaging apparatus 301 overland, thenormal control may be performed to switch still image shooting andmoving picture shooting through the switch operation.

Fourth Embodiment

An imaging apparatus according to a fourth embodiment of the presentinvention is characterized by switching the shooting mode depending on aholding form while the photographer is swimming immediately below thewater surface. A configuration of the imaging apparatus according to thefourth embodiment is the same as the configuration of the imagingapparatus 301 described in the third embodiment. The imaging apparatusaccording to the fourth embodiment will be referred to as an imagingapparatus 301.

In the fourth embodiment, like the second embodiment, still imageshooting or moving picture shooting is selected based on thecharacteristics (see FIG. 11) of the usage situation of the imagingapparatus 301, and thus the switch operation is defined. Specifically,when the photographer shoots underwater while skin diving (see FIG. 2),the imaging apparatus 301 changes the shooting conditions such asexposure and gain, and continuously shoots. When the photographer isswimming immediately below the water surface (see FIG. 18), the imagingapparatus 301 does the still image shooting when the photographer Mholds the imaging apparatus 301 with both hands, and does the movingpicture shooting when the photographer holds the imaging apparatus 301with either hand.

FIG. 25 is a flowchart showing an outline of processes to be performedby the imaging apparatus 301. FIG. 25 shows a case in which theacceleration detector 22 detects a tap or the hold detector 23 detects ahold (step S331: Yes). In this case, when the water depth changecalculator 7 refers to the result detected by the water depth detector 6and a value of the latest detection result can be regarded as underwater(step S332: Yes), the water depth change calculator 7 calculates theamount of change Δd between the two latest water depths detected by thewater depth detector 6 (step S333).

As a result of the calculation of the amount of change Δd in water depthby the water depth change calculator 7, when the absolute value |Δd| issmaller than the first threshold h and the water depth can be regardedas constant (step S334: Yes), the power supply controller 112 controlsthe power supply unit 12 to turn on and the display unit 4 displays theimage captured by the imaging unit 2 as through-image (step S335).Thereafter, when the release switch 5 a of the operation input unit 5 isoperated (step S336: Yes), the processes are differently performeddepending on the detection result by the hold detector 23. Specifically,as a result of the detection by the hold detector 23, when the imagingapparatus 301 is held by both hands (step S337: Yes), the imagingapparatus 301 performs the still image shooting (step S338) and returnsto step S331. To the contrary, as a result of the detection by the holddetector 23, when the imaging apparatus 301 is held by either hand (stepS337: No), the imaging apparatus 301 performs the moving pictureshooting (step S339) and returns to step S331.

When the release switch 5 a is not operated in step S336 (step S336:No), and a predetermined time has not elapsed after the power-on in stepS335 (step S340: No), the imaging apparatus 301 returns to step S336. Onthe other hand, when a predetermined time has elapsed after the power-onin step S335 (step S340: Yes), the imaging apparatus 301 proceeds tostep S350 described later.

There will be described below a case in which the absolute value |Δd| ofthe amount of change in water depth is equal to or more than the fourththreshold h₄ in step S334 (step S334: No). In this case, when the amountof change Δd in water depth is larger than the fifth threshold H₅ (stepS341: Yes), the power supply controller 112 turns on the power supply(step S342). Thereafter, when the release switch 5 a is operated (stepS343: Yes), the shooting controller 111 changes the shooting conditions(step S344) and then causes the imaging unit 2 to shoot (step S345). Thespecific process contents by the shooting controller 111 are the same asthose in the third embodiment.

When the amount of change Δd in water depth is equal to or less than thefifth threshold H₅ in step S341 (step S341: No) and the release switch 5a is not operated in step S343 (step S343: No), the imaging apparatus301 returns to step S331.

Steps S346 to S350 subsequent to step S345 sequentially correspond tosteps S108 to S112 in FIG. 20.

There will be described below a case in which the acceleration detector22 detects no tap and the hold detector 23 detects no hold in step S331(step S331: No) and a case in which the latest detection result by thewater depth detector 6 cannot be regarded as underwater in step S332(step S332: No). In the cases, the imaging apparatus 301 proceeds to themotion-sensing activation process (step S351). The details of themotion-sensing activation process are the same as those in the thirdembodiment (see FIG. 21).

After the motion-sensing activation process, when the imaging apparatus301 is in the power-on state (step S352: Yes), the imaging apparatus 301performs normal control (step S353). On the other hand, when the imagingapparatus 301 is not in the power-on state (step S352: No), the imagingapparatus 301 returns to step S331.

Subsequent to step S353, when the power supply is turned off by theoperation input unit 5 (step S354: Yes), the imaging apparatus 301proceeds to step S350. On the other hand, when the power supply is notturned off (step S354: No), the imaging apparatus 301 continues normalcontrol (step S353).

According to the fourth embodiment of the present invention describedabove, since the imaging apparatus is configured such that if therelease switch is pressed when the water depth is rapidly changing dueto diving, shooting is continuously performed predetermined number oftimes, a desired image is likely to be found in the continuously-shotimages even if the photographer is concentrating hard on swimming. Thus,the photographer can easily shoot while diving, and is likely to obtaindesired images.

According to the fourth embodiment, when the tap operation or holdoperation is detected underwater, and the water depth changes verylittle, power supplying is started to the entire imaging apparatus andthus the power supply can be easily turned on under an appropriatecondition during underwater shooting.

According to the fourth embodiment, when the tap operation or holdoperation is detected at a constant water depth, it is recognized thatthe photographer positively instructs the imaging apparatus to start theoperation, and the power supply is turned on, and thus the operation canbe more rapidly performed than pressing a small switch.

According to the fourth embodiment, since the power supply is turned offwhenever the photographer emerges underwater or the release signal isnot input, the battery can last long.

According to the fourth embodiment, since still image shooting andmoving picture shooting are switched depending on a holding form of theimaging apparatus by the underwater photographer, optimal control can beperformed depending on the underwater situation of the photographer.

In the third and fourth embodiments of the present invention describedabove, the photographer may shake the imaging apparatus to perform partof the switch operations.

Fifth Embodiment

FIG. 26 is a block diagram showing a configuration of an imagingapparatus according to a fifth embodiment of the present invention. Theimaging apparatus 401 shown in FIG. 26 includes the imaging unit 2, theimage processor 3, the display unit 4, the operation input unit 5, theclock 8, the auxiliary light projector 9, the power supply unit 12, theacceleration detector 22, an underwater detector 402 as a state detectorfor detecting whether the imaging apparatus 401 is underwater, a storageunit 403 for storing therein various items of information includingimage data processed by the image processor 3, and a control unit 404for controlling the operations of the imaging apparatus 401 depending onthe operation signals input by the operation input unit 5.

The underwater detector 402 is realized by a water pressure sensor, forexample, and detects a water pressure applied to the imaging apparatus401 to detect whether the imaging apparatus 401 is underwater. The waterpressure detected by the water pressure sensor is about 1060 hPa at awater depth of 50 cm, and becomes larger as the water depth is more. Theunderwater detector 402 can be realized by a water detection switchwhich is in a state of conduction by water between two electrodes.

The storage unit 403 includes the image data storage unit 101, theprogram storage unit 102, and a mode information storage unit 431 forstoring therein information on operation modes set by the imagingapparatus 401. The storage unit 403 is realized by a semiconductormemory such as flash memory or RAM fixedly provided inside the imagingapparatus 401. The storage unit 403 may function as a recording mediuminterface for recording information in an externally-mounted recordingmedium such as memory card and reading out information recorded in therecording medium.

The control unit 404 includes the shooting controller 111, the powersupply controller 112, and a display controller 441 for controlling adisplay in the display unit 4. The control unit 404 is realized by aCPU, and is connected to the respective parts in the imaging apparatus401 via a bus line.

The power supply unit 12 is always supplying power to the operationinput unit 5, the clock 8, the acceleration detector 22, the powersupply controller 112 and the underwater detector 402 irrespective ofwhether the imaging apparatus 401 has been activated by the power supplyswitch. Thus, the operation input unit 5, the clock 8, the accelerationdetector 22, the power supply controller 112 and the underwater detector402 are always being activated.

The above-configured imaging apparatus 401 has on its exterior awaterproof casing whose surfaces are tightly sealed like the imagingapparatus 1.

FIG. 27 is a diagram showing an operation's difficulty level and anecessity for play mode of the imaging apparatus in underwater shootingand overland shooting. Typically, the switches other than the releaseswitch are closely arranged in the imaging apparatus and theiroperations are more complicated than the release switch. Thus, it isdifficult to operate underwater the switches other than the releaseswitch in the imaging apparatus. The play mode does not need to be usedduring underwater shooting. It is not easy to finely adjust exposure orfocus underwater. In the imaging apparatus, the number of operationscapable of being easily performed underwater is less than that of theoverland operations. If various switches provided in the imagingapparatus are operable like overland, an unstable posture can causeerroneous operations underwater.

In the fifth embodiment, the individual switch operations other than therelease switch 5 a are performed by tapping the imaging apparatus 401during underwater shooting in consideration of the difference betweenunderwater shooting and overland shooting. In this case, since the tapoperation is performed in the same manner, the setting of the operationmodes (operation contents) is changed depending on the number of timesof tapping. Specifically, there is performed an operation correspondingto a remainder obtained by dividing the number of times of tapping by apredetermined number.

FIG. 28 is a diagram showing the contents of the operation control bythe control unit 404 depending on the number of times of tap operationin the underwater shooting mode. The information shown in FIG. 28 isstored in the mode information storage unit 431.

When the first tap operation is performed in the imaging apparatus 401,the control unit 404 turns on the power supply and sets the operationmode of the imaging apparatus 401 in the still image shooting mode.

When the second tap operation is performed in the imaging apparatus 401,the control unit 404 switches the operation mode to the strobe-on modein which the auxiliary light projector 9 projects an auxiliary lightduring shooting.

When the third tap operation is performed in the imaging apparatus 401,the control unit 404 switches the operation mode to the strobe-off modein which the auxiliary light projector 9 does not project an auxiliarylight during shooting.

When the fourth tap operation is performed in the imaging apparatus 401,the control unit 404 switches the operation mode to the moving pictureshooting mode.

When the fifth tap operation is performed in the imaging apparatus 401,the control unit 404 turns off the power supply.

For the sixth and subsequent tap operations in the imaging apparatus401, the modes are set based on the number of times of operationcorresponding to a remainder obtained by dividing the number of times ofoperation by a predetermined number of 5. For example, since a remainderobtained by dividing 6 by 5 is 1 when the sixth tap operation isperformed, the power supply controller 112 turns on the power supplylike when the first tap operation is performed, and the control unit 11sets the operation mode in the still image shooting mode.

The correspondence between the number of times of tap operation and theoperation control contents may be set by the user. For example, a listof operation contents including the operations shown in FIG. 28 isdisplayed by the display unit 4 and the number of times of tap operationcorresponding to each operation may be set by user's writing in theoperation input unit 5. A desired operation may be selected from thelist of operation contents. The operation contents in the list may berearranged. The instruction signals for writing, selecting andrearranging may be input through the arrow key or the touch panelprovided in the operation input unit 5, for example.

FIG. 29 is a flowchart showing an outline of processes when the imagingapparatus 401 is set in the underwater shooting mode. When theunderwater detector 402 decides that the imaging apparatus 401 isunderwater (step S401: Yes) and when the acceleration detector 22detects the tap operation (step S402: Yes), the control unit 11 switchesthe mode depending on the number of times of operation. The decision instep S401 can detect whether the imaging apparatus 401 is underwater.Additionally, step S401 may be configured to discriminate a case inwhich the imaging apparatus 401 is underwater and the photographershoots while swimming from a case in which the imaging apparatus 401 isunderwater and the photographer shoots while changing the water depth,and may be configured to decide, only while the photographer isswimming, that the imaging apparatus 401 is underwater. Thus, it ispossible to prevent erroneous operations which can be caused bystrenuous movement during diving.

When the tap operation detected by the acceleration detector 22 in stepS402 is the power-off operation (corresponding to the fifth operation inFIG. 28) (step S403: Yes), the power supply controller 112 turns off thepower supply (step S404) and returns to step S401.

When the tap operation detected by the acceleration detector 22 in stepS402 is not the power-off operation (step S403: No) but the power-onoperation (corresponding to the first operation) (step S405: Yes), thepower supply controller 112 turns on the power supply (step S406) andproceeds to step S408 described later. On the other hand, when the tapoperation in step S402 is not the power-on operation (step S405: No),the control unit 404 switches the operation mode depending on the numberof times of operation (step S407). Specifically, the mode is switched toany one of the strobe-on mode (corresponding to the second operation),the strobe-off mode (corresponding to the third operation) and themoving picture shooting mode (corresponding to the fourth operation).

Subsequently, the display unit 4 displays the information on theoperation modes set under control of the display controller 441 (stepS408). FIG. 30 is a diagram showing the display contents of the displayunit 4 in this case. The display unit 4 displays the operation mode in asingle color and enlarges the textual information indicating theoperation mode (“still image” in FIG. 30) as main information inconsideration of underwater shooting. When the display unit 4 isrealized by a liquid crystal display panel, a luminance of the liquidcrystal backlight is preferably enhanced.

FIG. 31 is a diagram showing another display example of the display unit4. As shown in FIG. 31, the display unit 4 can list the selectable modesand display the currently-selected display with a frame f in anemphasized manner. When the user can set the correspondence between thenumber of times of operation and the operation control contents, thelist of operation contents can be displayed in the form shown in FIG.31.

After step S408, when the release operation is performed (step S409:Yes), the shooting controller 111 performs shooting control depending onthe set operation mode (step S410). Then, when the acceleration detector22 detects the tap operation (step S411: Yes), the imaging apparatus 401returns to step S403. On the other hand, when the acceleration detector22 does not detect the tap operation (step S411: No), after apredetermined time has elapsed since the display of the operation modeby the display unit 4 (step S412: Yes), the power supply controller 112controls the power supply unit 12 to turn off (step S413). Thereafter,the imaging apparatus 401 returns to step S401. If a predetermined timehas not elapsed since the display of the operation mode by the displayunit 4 (step S412: No), the imaging apparatus 401 returns to step S409.

When the release operation is not performed in step S409 (step S409:No), the imaging apparatus 401 proceeds to step S412.

When the underwater detector 402 decides that the imaging apparatus isnot underwater in step S401 (step S401: No) and when the accelerationdetector 22 does not detect the tap operation in step S402 (step S402:No), the imaging apparatus 401 returns to step S401.

According to the fifth embodiment of the present invention describedabove, the operation control is performed depending on a remainderobtained by dividing the number of times of detecting a predeterminedunderwater operation by a predetermined number, thereby simplifying theoperations to be performed by the photographer. Thus, the operationsduring underwater shooting can be easily and accurately performed.Erroneous operations can be prevented underwater.

In the fifth embodiment, the inputs through the operation switches otherthan the release switch 5 a are all regarded as the same, and can beused instead of the tap input. FIG. 32 is a diagram showing an outerconfiguration of the rear surface of the imaging apparatus 401. The rearsurface of the imaging apparatus 401 is provided with the display unit 4and further a group of switches 5G made of various operation switchesother than the release switch 5 a. There may be configured such thatwhen the imaging apparatus 401 is underwater, even if any of the variousswitches in the group of switches 5G is pressed, the same operationsignal is considered being input and the mode is set depending on thenumber of times of operation based on the correspondence shown in FIG.28. The input through the group of switches 5G and the input throughtapping can be used together.

In the fifth embodiment, when the underwater shooting mode is set, theoperation control contents of the control unit 404 based on the numberof times of tap operation can be appropriately changed. FIG. 33 is adiagram showing other setting contents depending on the number of timesof tap operation. FIG. 33 shows six setting patterns.

When the first tap operation is performed in the imaging apparatus 401,the control unit 404 turns on the power supply and sets the operationmode of the imaging apparatus 401 in the still image shooting mode.

When the second tap operation is performed in the imaging apparatus 401,the control unit 404 sets the operation mode in the macro mode.

When the third tap operation is performed in the imaging apparatus 401,the control unit 404 sets the operation mode in the closeup mode.

When the fourth tap operation is performed in the imaging apparatus 401,the control unit 404 sets the operation mode in the strobe-off mode.

When the fifth tap operation is performed in the imaging apparatus 401,the control unit 404 sets the operation mode in the moving pictureshooting mode.

When the sixth tap operation is performed in the imaging apparatus 401,the control unit 404 turns off the power supply.

When the seventh and subsequent tap operations are performed in theimaging apparatus 401, the mode is set based on the number of times ofoperation corresponding to a remainder obtained by dividing the numberof times of operation by 7.

Sixth Embodiment

A sixth embodiment of the present invention is configured such that theswitches other than the release switch are disabled in the underwatershooting mode and are operated by pressing the release switch halfway.The configuration of the imaging apparatus according to the sixthembodiment is the same as the configuration of the imaging apparatus401. The imaging apparatus according to the sixth embodiment will bereferred to as an imaging apparatus 401 below.

FIG. 34 is a flowchart showing an outline of processes when the imagingapparatus 401 is set in the underwater shooting mode. There will befirst described a case in which the underwater detector 402 detects thatthe imaging apparatus 401 is underwater (step S521: Yes). In this case,when the release switch 5 a is pressed (step S522: Yes) and the powersupply is in the power-on state (step S523: Yes), the imaging apparatus401 performs shooting control (step S524) and returns to step S521. Onthe other hand, when the power supply is not in the power-on state (stepS523: No), the power supply controller 112 controls the power supplyunit 12 to turn on (step S525). When the underwater detector 402 detectsthat the imaging apparatus 401 is not underwater (step S521: No), theimaging apparatus 401 repeats step S521. The decision in step S521 candiscriminate a case in which the imaging apparatus 401 is underwater andthe photographer shoots while swimming from a case in which the imagingapparatus 401 is underwater and the photographer shoots while changingthe water depth, and may decide that the imaging apparatus is underwateronly when the photographer is swimming, like step S401 of FIG. 29.

Subsequent to step S525, the control unit 404 disables the switchesother than the release switch 5 a (step S526).

Thereafter, when the release switch 5 a is pressed halfway (step S527:Yes), the control unit 404 performs the operation control depending onthe number of times of pressing the release switch halfway (step S528).A relationship between the number of times of pressing the releaseswitch halfway and the operation control contents is the same as thatdescribed in the fifth embodiment (see FIG. 28).

Subsequently, the display unit 4 displays the information on the setoperation mode (step S529). The display contents on the display unit 4in step S529 are the same as those described in the fifth embodiment(see FIG. 30).

Then, when the release operation is performed (step S530: Yes), theimaging apparatus 401 performs the shooting control depending on theoperation mode (step S531), and then resets the operation mode (stepS532) and returns to step S521.

On the other hand, when the release operation is not performed (stepS530: No), if a predetermined time has elapsed since the display of theoperation mode by the display unit 4 (step S533: Yes), the imagingapparatus 401 proceeds to step S532. To the contrary, if a predeterminedtime has not elapsed since the display of the operation mode by thedisplay unit 4 (step S533: No), the imaging apparatus 401 returns tostep S521.

When the release switch 5 a is not pressed halfway in step S527 (stepS527: No), and a predetermined time has elapsed since the disablement ofthe switches other than the release switch 5 a (step S534: Yes), theimaging apparatus 401 proceeds to step S532. On the other hand, if apredetermined time has not elapsed since the disablement of the switchesother than the release switch 5 a in step S534 (step S534: No), theimaging apparatus 401 returns to step S527.

There will be described below a case in which the release switch 5 a isnot pressed in step S522 (step S522: No). When the power supply switchis operated (step S535: Yes) and the operation is the power-offoperation (step S536: Yes), the power supply controller 112 turns offthe power supply (step S537). Then the imaging apparatus 401 returns tostep S521.

On the other hand, when the power supply switch is operated (step S535:Yes) and the operation is not the power-off operation (step S536: No),the power supply controller 112 controls the power supply unit 12 toturn on (step S538). In this case, when the mode switching operation isfurther performed (step S539: Yes), the control unit 404 switches theoperation mode depending on the switch operation (step S540). Then theimaging apparatus 401 proceeds to step S530.

When the power supply switch is not operated in step S535 (step S535:No) and the mode switching operation is not performed in step S539 (stepS539: No), the imaging apparatus 401 returns to step S521.

According to the sixth embodiment of the present invention, there isperformed the operation control defined depending on a remainderobtained by dividing the number of times of detecting a predeterminedunderwater operation by a predetermined number, thereby simplifying theoperations to be performed by the photographer. Thus, the operationsduring the underwater shooting can be easily and accurately performed.Also erroneous operations can be prevented underwater.

According to the sixth embodiment, since the operation of pressinghalfway the release switch to be used for overland focus lock cannot beutilized underwater, another function is assigned to the operation ofpressing the release switch halfway. Consequently, the photographer canperform all the operations by one finger underwater.

Seventh Embodiment

In a seventh embodiment of the present invention, when the photographerholds the imaging apparatus with both hands in the underwater shootingmode, a tap by the left hand which does not operate the release switchis regarded as a signal input other than release signal. On the otherhand, when the photographer holds the imaging apparatus with only theright hand in the underwater shooting mode, the right hand's shaking orthe input through the group of switches other than the release switch isregarded as signal input other than release signal.

FIG. 35 is a block diagram showing a configuration of an imagingapparatus according to the seventh embodiment of the present invention.The imaging apparatus 521 shown in FIG. 35 includes the hold detector 23like the imaging apparatus 21 in addition to the configuration of theimaging apparatus 401.

In the above-configured imaging apparatus 521, the positions of thehands holding the imaging apparatus 521 are detected and the imagingapparatus 521 is controlled depending on the tapping or shakingoperation input.

FIG. 36 is a flowchart showing an outline of processes to be performedby the imaging apparatus according to the seventh embodiment of thepresent invention. There will be first described a case in which theunderwater detector 402 detects that the imaging apparatus 521 isunderwater (step S651: Yes), the acceleration detector 22 detects a tapfrom the left surface of the imaging apparatus 521 viewed from the rearsurface thereof (step S652: Yes) and the hold detector 23 detects thatthe imaging apparatus 521 is held by both hands (step S653: Yes). Whenthe underwater detector 402 detects that the imaging apparatus 521 isnot underwater in step S651 (step S651: No), the imaging apparatus 521repeats step S651. The underwater decision in step S651 may discriminatea case in which the imaging apparatus 521 is underwater and thephotographer shoots while swimming from a case in which the imagingapparatus 521 is underwater and the photographer shoots while changingthe water depth like step S401 of FIG. 29, and may decide that theimaging apparatus 521 is underwater only when the photographer isswimming underwater.

Thereafter, the control unit 404 performs the operation controldepending on the number of times of tap operation (step S654). Arelationship between the number of times of operation and the operationcontrol contents is the same as that of the fifth embodiment (see FIG.28). FIG. 37 is a diagram showing a situation in which the photographerM holds the imaging apparatus 521 with both hands and is ready to shoot.As shown in FIG. 37, when the photographer M is swimming immediatelybelow the water surface, the photographer M can use both hands forshooting. As shown in FIG. 38, the right hand RH only operates therelease switch 5 a of the imaging apparatus 521 and the left hand LH'sforefinger LHf taps the surface of the imaging apparatus 521 so that theoperation mode may be switched.

Subsequent to step S654, the display unit 4 displays the information onthe set operation mode (step S655). Then, when the release operation isperformed through the release switch 5 a (step S656: Yes), the shootingcontroller 111 performs the shooting control depending on the set mode(step S657). Thereafter, the imaging apparatus 521 returns to step S651.When the release operation is not performed in step S656 (step S656:No), the imaging apparatus 521 repeats step S656.

When the hold detector 23 does not detect that the imaging apparatus isnot held by both hands in step S653 (step S653: No), the imagingapparatus 521 returns to step S651.

There will be described below a case in which the acceleration detector22 does not detect a tap from the left surface (step S652: No) and firstdetects shaking from the right side to the left side (step S658: Yes).In this case, when the hold detector 23 detects that the imagingapparatus 521 is held by the right hand (step S659: Yes), the imagingapparatus 521 proceeds to step S654. On the other hand, when the holddetector 23 does not detect that the imaging apparatus 521 is held bythe right hand (step S659: No), the imaging apparatus 521 returns tostep S651.

FIG. 39 is a diagram showing a situation in which the photographer Mholds the imaging apparatus 521 by the right hand and is ready to shoot.As shown in FIG. 39, when the photographer is underwater, he/she usesthe left hand for swimming because of the positional relationship withthe release switch 5 a. Thus, the left hand is difficult to use foroperating the imaging apparatus 521 under the situation of FIG. 39. Inthe seventh embodiment, the right hand's shaking functions as switchoperation.

When the acceleration detector 22 does not detect the shaking in stepS658 (step S658: No) and a switch other than the release switch 5 a andthe power supply switch (other switch operation) is operated (step S660:Yes), the imaging apparatus 521 proceeds to step S659.

In this way, in the seventh embodiment, when the imaging apparatus 521is not tapped or shaken, other switch operation is operated, and theimaging apparatus 521 is held by the right hand, the control unit 404performs the operation control depending on the number of times of otherswitch operation. In this sense, in the seventh embodiment, when theimaging apparatus 521 is not tapped or shaken and the imaging apparatus521 is held by the right hand, other switch operations are all regardedas the same.

When other switch is not operated in step S660 (step S660: No) and whenthe power supply switch 5 b is operated (step S661: Yes), if the powersupply switch operation is the power-off operation (step S662: Yes), thepower supply controller 112 controls the power supply unit 12 to turnoff (step S663). Thereafter, the imaging apparatus 521 returns to stepS651.

When the power supply switch operation is not the power-off operation instep S662 (step S662: No), the power supply controller 112 controls thepower supply unit 12 to turn on (step S664). Subsequently, when the modeswitching is operated (step S665: Yes), the control unit 404 switchesthe operation mode depending on the switch operation (step S666). Thenthe imaging apparatus 521 proceeds to step S655.

When the power supply switch is not operated in step S661 (step S661:No) and the mode switching is not performed in step S665 (step S665:No), the imaging apparatus 521 returns to step S651.

According to the seventh embodiment of the present invention describedabove, there is performed the operation control defined depending on aremainder obtained by dividing the number of times of detecting apredetermined underwater operation by a predetermined number, therebysimplifying the operations to be performed by the photographer. Thus,the operations during the underwater shooting can be easily andaccurately performed. Further, erroneous operations can be preventedunderwater.

In the seventh embodiment, the switch operation may be performed bychanging a pressure by a photographer's hand or finger holding theimaging apparatus 521. In this case, the presence of the operation inputis decided based on a change in pressure detected by the hold detector23.

The techniques described in the first to seventh embodiments can beappropriately selected or combined depending on product's concept oruser's preference. The first to seventh embodiments are appropriatelyselected or combined, thereby realizing the imaging apparatus capable ofbeing suitably operated depending on the usage environment or usagesituation.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. An imaging apparatus comprising: an imaging unitfor capturing a subject and generating image data of the subject; anoperation input unit for receiving inputs of operation signalscontaining a release signal for instructing the imaging unit to shoot;an acceleration detector for detecting an acceleration of the imagingapparatus; a state detector for separately detecting a case in which theimaging apparatus is overland, a case in which the imaging apparatus isunderwater and a photographer shoots while swimming, and a case in whichthe imaging apparatus is underwater and the photographer shoots whilechanging a water depth, the state detector including a water depthdetector for detecting a water depth at a predetermined period when theimaging apparatus is underwater, and a water depth change calculator forcalculating the amount of change in water depth detected by the waterdepth detector; a power supply unit for supplying power to predeterminedparts containing the imaging unit; a hold detector for detecting anexternal hold based on a pressure applied to a predetermined area; and acontrol unit for performing operation control depending on an input intothe operation input unit and/or into the acceleration detector accordingto a state detection result by the state detector, the control unitincluding a power supply controller for controlling power supplying bythe power supply unit, wherein the control unit controls the imagingunit to continuously shoot predetermined number of times when therelease signal is input from the operation input unit and the amount ofchange in water depth calculated by the water depth change calculator islarger than a first threshold of predetermined positive number, whereinwhen the release signal is input from the operation input unit and theamount of change in water depth calculated by the water depth changecalculator is larger than the first threshold, the control unit sets anexposure time of the imaging unit to be shorter than an initial setting,controls a gain of the imaging unit to be higher than an initialsetting, and then controls the imaging unit to continuously shoot thepredetermined number of times, wherein when the amount of change betweenthe two latest water depths calculated by the water depth changecalculator is larger than the first threshold, the power supplycontroller transits to a state in which the power supply unit can supplypower to the entire imaging apparatus, and wherein when the accelerationdetector detects a pulse shaped acceleration having a magnitude largerthan a predetermined value or the hold detector detects a hold having apressure larger than a predetermined pressure while the power supplyunit stops supplying power to parts other than the always-on partscontaining the acceleration detector, the hold detector, the operationinput unit, the water depth detector, the water depth change calculatorand the power supply controller, the water depth change calculatorcalculates the amount of change between two latest water depths detectedby the water depth detector.
 2. The imaging apparatus according to claim1, wherein the control unit switches shooting control of the image datain response to an input into the operation input unit according to astate detection result by the state detector.
 3. The imaging apparatusaccording to claim 1, wherein when the release signal is input while thepower supply unit stops supplying power to parts other than thealways-on parts containing the operation input unit, the water depthdetector, the water depth change calculator and the power supplycontroller, the water depth change calculator calculates the amount ofchange between two latest water depths detected by the water depthdetector.
 4. The imaging apparatus according to claim 1, wherein whenthe acceleration detector detects a pulse-shaped acceleration having amagnitude larger than a predetermined value while the power supply unitstops supplying power to parts other than the always-on parts containingthe acceleration detector, the operation input unit, the water depthdetector, the water depth change calculator and the power supplycontroller, the water depth change calculator calculates the amount ofchange between two latest water depths detected by the water depthdetector, and when the amount of change between the two latest waterdepths calculated by the water depth change calculator is larger thanthe first threshold and the release signal is input, the power supplycontroller transits to a state in which the power supply unit can supplypower to the entire imaging apparatus.
 5. The imaging apparatusaccording to claim 1, wherein when the amount of change between the twolatest water depths calculated by the water depth change calculator islarger than the first threshold and the release signal is input, thepower supply controller transits to a state in which the power supplyunit can supply power to the entire imaging apparatus.
 6. The imagingapparatus according to claim 5, wherein the hold detector detectspressures applied to two areas provided at both ends in a longitudinaldirection of the imaging apparatus, respectively, and the control unitcontrols the imaging unit for still image shooting when the holddetector detects pressures larger than a predetermined pressure in thetwo areas, and controls the imaging unit for moving picture shootingwhen the hold detector detects a pressure larger than the predeterminedpressure in one of the two areas closer to a release switch throughwhich the release signal is input.
 7. The imaging apparatus according toclaim 1, wherein the water depth change calculator calculates the amountof change between two latest water depths detected by the water depthdetector when an operation signal other than the release signal is inputthrough the operation input unit while the imaging unit is able toshoot, and the power supply controller stops power supplying by thepower supply unit to parts other than the always-on parts when theamount of change between the two latest water depths calculated by thewater depth change calculator is smaller than a second threshold havinga different sign from the first threshold.
 8. The imaging apparatusaccording to claim 1, wherein the water depth detector includes a waterpressure sensor for detecting a water pressure applied to the imagingapparatus.
 9. The imaging apparatus according to claim 2, wherein thepower supply unit always supplies power to the water depth detector, theacceleration detector, the water depth change calculator and the powersupply controller, and when the acceleration detector detects apulse-shaped acceleration having a magnitude larger than a predeterminedvalue and when the absolute value of the amount of change between twolatest water depths calculated by the water depth change calculator issmaller than a fourth threshold of predetermined positive number, thepower supply controller transits to a state in which the power supplyunit can supply power to the entire imaging apparatus.
 10. The imagingapparatus according to claim 9, further comprising: a shootingcontroller for controlling the imaging unit to shoot, wherein theoperation input unit is always supplied with power by the power supplyunit for receiving inputs of operation signals containing a releasesignal for instructing the imaging unit to shoot, and wherein theshooting controller controls the imaging unit to continuously shootpredetermined number of times when the release signal is input from theoperation input unit and the amount of change in water depth calculatedby the water depth change calculator is larger than a fifth thresholdset to be larger than the fourth threshold.
 11. The imaging apparatusaccording to claim 10, wherein when the amount of change in water depthcalculated by the water depth change calculator is larger than the fifththreshold and the release signal is input from the operation input unit,the shooting controller sets an exposure time of the imaging unit to beshorter than an initial setting, controls a gain of the imaging unit tobe higher than an initial setting, and then controls the imaging unit tocontinuously shoot predetermined number of times.
 12. The imagingapparatus according to claim 11, wherein when the release signal isinput while the power supply unit stops supplying power to parts otherthan the always-on parts containing the operation input unit, the waterdepth detector, the acceleration detector, the water depth changecalculator and the power supply controller, the water depth changecalculator calculates a change between two latest water depths detectedby the water depth detector, and when the amount of change between thetwo latest water depths calculated by the water depth change calculatoris larger than the fifth threshold, the power supply controller transitsto a state in which the power supply unit can supply power to the entireimaging apparatus.
 13. The imaging apparatus according to claim 10,wherein the water depth change calculator calculates the amount ofchange between two latest water depths detected by the water depthdetector when an operation signal other than the release signal is inputthrough the operation input unit while the imaging unit is able toshoot, and the power supply controller stops power supplying by thepower supply unit to parts other than the always-on parts when theamount of change between the two latest water depths calculated by thewater depth change calculator is smaller than a sixth threshold having adifferent sign from the fifth threshold.
 14. The imaging apparatusaccording to claim 10, wherein the hold detector detects pressuresapplied to two areas provided at both ends in a longitudinal directionof the imaging apparatus, and the shooting controller controls theimaging unit for still image shooting when the hold detector detectspressures larger than a predetermined pressure in the two areas, andcontrols the imaging unit for moving picture shooting when the holddetector detects a pressure larger than the predetermined pressure inone of the two areas closer to a release switch through which therelease signal is input.
 15. The imaging apparatus according to claim 9,wherein the water depth detector includes a water pressure sensor fordetecting a water pressure applied to the imaging apparatus.
 16. Theimaging apparatus according to claim 9, wherein the accelerationdetector further comprises a posture decision unit for detectingcomponents of a gravity acceleration at a predetermined period in athree-dimensional orthogonal coordinate system fixed in the imagingapparatus when the imaging apparatus is overland, and for deciding aposture of the imaging unit by using the components of the gravityacceleration detected by the acceleration detector, and when the posturedecision unit decides that the imaging apparatus is ready to shoot inits posture, the power supply controller transits to a state in whichthe power supply unit can supply power to the entire imaging apparatus.17. The imaging apparatus according to claim 1, wherein when the statedetector detects that the imaging apparatus is underwater and when theacceleration detector detects a pulse-shaped acceleration having amagnitude larger than a predetermined value, the control unit performsoperation control based on the number of times of operationcorresponding to a remainder obtained by dividing the number of times ofdetecting the pulse-shaped acceleration by the total number ofunderwater-settable operation contents.
 18. The imaging apparatusaccording to claim 17, wherein the power supply unit always suppliespower to the operation input unit, the state detector, the accelerationdetector and the power supply controller, and the power supplycontroller transits to a state in which the power supply unit can supplypower to the entire imaging apparatus when the remainder is
 1. 19. Theimaging apparatus according to claim 18, wherein the power supplycontroller controls the power supply unit to stop supplying power toparts other than the always-on parts when the remainder is maximum. 20.The imaging apparatus according to claim 1, wherein when the statedetector detects that the imaging apparatus is underwater, the controlunit regards inputs into multiple switches other than the release switchas identifiable, and performs operation control defined depending on aremainder obtained by dividing the number of times of inputting from theidentifiable switches by the total number of underwater-settableoperation contents.
 21. The imaging apparatus according to claim 20,wherein the power supply unit always supplies power to the operationinput unit, the state detector and the power supply controller, and thepower supply controller transits to a state in which the power supplyunit can supply power to the entire imaging apparatus when the remainderis
 1. 22. The imaging apparatus according to claim 21, wherein the powersupply controller controls the power supply unit to stop supplying powerto parts other than the always-on parts when the remainder is maximum.23. The imaging apparatus according to claim 1, wherein when the statedetector detects that the imaging apparatus is underwater, the controlunit disables the inputting into multiple switches other than therelease switch, and performs operation control defined depending on aremainder obtained by dividing the number of times of pressing therelease switch halfway by the total number of underwater-settableoperation contents.
 24. The imaging apparatus according to claim 23,wherein the power supply unit always supplies power to the operationinput unit, the state detector and the power supply controller, and thepower supply controller transits to a state in which the power supplyunit can supply power to the entire imaging apparatus when the remainderis
 1. 25. The imaging apparatus according to claim 24, wherein the powersupply controller controls the power supply unit to stop supplying powerto parts other than the always-on parts when the remainder is maximum.26. The imaging apparatus according to claim 1, wherein when the statedetector detects that the imaging apparatus is underwater, when theacceleration detector detects a pulse-shaped acceleration having amagnitude larger than a predetermined value, and when a detection resultby the acceleration detector and a detection result by the hold detectormeet a predetermined correspondence, the control unit performs operationcontrol defined depending on a remainder obtained by dividing the numberof times of detecting the pulse-shaped acceleration by the total numberof underwater-settable operation contents.
 27. The imaging apparatusaccording to claim 26, wherein the power supply unit always suppliespower to the operation input unit, the state detector, the accelerationdetector, the hold detector and the power supply controller, and thepower supply controller transits to a state in which the power supplyunit can supply power to the entire imaging apparatus when the remainderis
 1. 28. The imaging apparatus according to claim 27, wherein the powersupply controller controls the power supply unit to stop supplying powerto parts other than the always-on parts when the remainder is maximum.29. The imaging apparatus according to claim 17, further comprising: adisplay unit for displaying information containing image data generatedby the imaging unit, wherein when the state detector detects that theimaging apparatus is underwater, the control unit displays textualinformation indicating the operation contents defined depending on theremainder as main information on the display unit.